Aerogel Sintering: From Optical Glasses to Nuclear Waste Containment Auteur(s): Phalippou Jean, Dieudonne-George P., Faivre A., Woignier Thierry Chapître d'ouvrage: Handbook Of Sol-Gel Science And Technology Processing: Characterization And Applications, vol. p.1949 - 1969 (2018) Texte intégral en Openaccess : Ref HAL: hal-01929789_v1 DOI: 10.1007/978-3-319-32101-1_56 Exporter : BibTex | endNote Résumé: Aerogels are ultraporous materials with a very low permeability. They exhibithigh specific surface area but, due to their huge porous volume, their mechanical properties are quite poor. Aerogels belong to two main families: inorganic materials as silica, silicates, and a few aluminates and organic aerogels which are easily transformed into carbon aerogels by a simple pyrolysis thermal treatment. In this chapter, we mainly report experiments performed on alcohol-dried aerogels. Due to their broad range of porosity, aerogels canfitin very different applications: from analysis of cosmic dust to nuclear waste containment glasses. Advantages of large porosity are sometimes used directly like in thermal and acoustic insulation, or in catalyzers, but a too high pore volume can also be a drawback like in glass precursor and host matrix. Fortunately, aerogel porosity can be tailored using sintering or room isostatic compression or eventually a combination of both methods. Knowledge in this area allows now to synthesize aerogels with a broad range of porosity and also a very broad range of texture. |